Coke ovens play a very substantial part in today's manufacturing industry. Although there are many different types, designs and styles of coke ovens, which depend largely upon the resources and specific requirements of the user, they all have many common characteristics and problems associated therewith.
For example, most coke ovens comprise a plurality of vertically-oriented combustion chamber assemblies spaced laterally from one another. The space defined between the outside wall surfaces of two adjacent combustion chamber assemblies is the heating chamber wherein the coal is transformed into coke and other useful by-products.
Each combustion chamber assembly, itself, comprises a plurality of vertically-oriented combustion flues separated from one another by interior dividing walls. These dividing walls are generally perpendicular to, and abut against, the inside wall surface of the combustion chamber assembly side walls.
Moreover, in most conventional combustion chamber assemblies, a "sight hole" is positioned at the upper end of the assembly. This "sight hole", which is generally aligned with the longitudinal axis of, and opens into, each combustion flue, is for manually looking into the combustion flue to see if there are any obstructions therein (e.g., refractory wall blocks which have shifted or fallen) and/or checking flue temperature.
In most conventional coke ovens, there are many structural requirements for their combustion chamber assemblies. These requirements often make the combustion assemblies difficult and costly to design and construct.
One example of a structural requirement is that, in many of the conventional coke ovens, adjacent combustion flues, within a particular combustion chamber assembly, operate in alternating "combustion" and "regeneration" modes. In other words, while one combustion flue is in the "up" or "combustion" mode, the adjacent combustion flues, within the same combustion chamber assembly, are in the "down" or "regeneration" mode. Then, after a predetermined period of time (e.g., from between about a half an hour to about an hour), those flues which are in the combustion mode are cycled to the regeneration mode and vice versa. In order for this cycling of combustion and regenerating gases to be energy efficient, gas seepage between adjacent combustion flues must be minimized.
In conventional coke ovens which employ such a cycling process of combustion and regeneration gases, the dividing wall separating adjacent combustion flues of a combustion chamber assembly generally consists of staggered refractory blocks which are laid one on top of another (see, e.g. FIG. 1 which will be discussed later). These blocks, which span the entire width of the combustion flue, and which have at least one straight "head joint" (i.e., the joint between the dividing wall end surfaces and the inside surface of the combustion chamber side walls) are typically mortared in place. The mortar and the abutting relationship at the "head joints" are conventionally relied upon to provide the seal between adjacent combustion flues.
Seals conventionally made by this manner, however, quickly deteriorate when subjected to the normal conditions encountered in typical coke ovens. Specifically, due to the alternating flow patterns of combustion and regeneration gases, there are rapid and large temperature swings within the individual combustion flues. This rapid and drastic temperature change results in a "thermal shock" to the construction material (e.g., silica blocks) which makes up both, the combustion flue dividing walls and the combustion chamber assembly outside walls. This thermal shock, in turn, causes the construction material to expand and contract.
As can be expected, the continual expansion and contraction of the refractory material causes the mortar seals at the head joints between the longitudinal ends of the combustion flue dividing walls and the combustion chamber assembly outside walls to deteriorate. Consequently, gas seepage often occurs between adjacent combustion flues, thus, greatly reducing the energy efficiency of the coke oven.
Due to the continual rising costs of energy sources, and the increasing public concern for energy conservation, the manufacturing industry would greatly welcome a means by which combustion chamber assemblies can be manufactured such that they provide an energy efficient seal between adjacent combustion flues.
Another structural requirement of combustion chamber assemblies is that they must be tapered along their horizontal axis. The purpose of this taper is to facilitate the expulsion of the coke from the heating chamber which has been formed therein.
Because of this taper, many different sized blocks are needed to construct combustion chamber assemblies. For the builder of such combustion chamber assemblies, this generally means that they need to have a large inventory of many different block sizes and shapes. This problem even is further compounded by the fact that no two coke ovens are identical.
In view of the above, the industry would also welcome a means of simplifying the construction of combustion chamber assemblies, regardless of the specific structural requirements of individual coke ovens.
As stated earlier, another structural requirement of combustion chamber assemblies is that they should have a means for visually observing whether there is blockage within the individual combustion flues (e.g., a "sight hole"). While often necessary, the construction of this "sight hole" also creates many problems for the person constructing the combustion chamber assembly. For example, sight holes are typically constructed from a plurality of different sized and shaped construction blocks. This, as with the conventional means for constructing the combustion flues within a combustion chamber assembly, even further increases the number of different sized and shaped blocks needed to construct such an assembly unit. As before, the industry would greatly welcome a means by which the construction of sight holes, within a combustion chamber assembly, is simplified.